The present disclosure relates to a coordinate measuring machine, and in particular to a portable articulated arm coordinate measuring machine having a system for retaining and storing a probe end of the articulated arm.
Portable articulated arm coordinate measuring machines (AACMMs) have found widespread use in the manufacturing or production of parts where there is a need to rapidly and accurately verify the dimensions of the part during various stages of the manufacturing or production (e.g., machining) of the part. Portable AACMMs represent a vast improvement over known stationary or fixed, cost-intensive and relatively difficult to use measurement installations, particularly in the amount of time it takes to perform dimensional measurements of relatively complex parts. Typically, a user of a portable AACMM simply guides a probe along the surface of the part or object to be measured. The measurement data are then recorded and provided to the user. In some cases, the data are provided to the user in visual form, for example, three-dimensional (3-D) form on a computer screen. In other cases, the data are provided to the user in numeric form, for example when measuring the diameter of a hole, the text “Diameter=1.0034” is displayed on a computer screen.
An example of a prior art portable articulated arm CMM is disclosed in commonly assigned U.S. Pat. No. 5,402,582 ('582), which is incorporated herein by reference in its entirety. The '582 patent discloses a 3-D measuring system comprised of a manually-operated articulated arm CMM having a support base on one end and a measurement probe at the other end. Commonly assigned U.S. Pat. No. 5,611,147 ('147), which is incorporated herein by reference in its entirety, discloses a similar articulated arm CMM. In the '147 patent, the articulated arm CMM includes a number of features including an additional rotational axis at the probe end, thereby providing for an arm with either a two-two-two or a two-two-three axis configuration (the latter case being a seven axis arm).
Typically, the probe end of the arm is allowed to freely rotate about two or three axes, care must be taken, during shipment or storage for example, to avoid damaging the probe during use. Typically a strap, such as one having a hook and loop fastener for example, is used to hold the probe end against the adjacent arm segment during shipping. It should be appreciated that while the strap is convenient for shipping purposes, it is undesirable for use in operations since the dangling strap ends may interfere with the use of the arm or the probe.
Accordingly, while existing AACMM's are suitable for their intended purposes there remains a need for improvements, particularly in the securing of the probe when the articulated arm is shipped or not in use.